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Post-Modern History

Reformulated the concept of time and space (E = mc² => special relativity)

Time is not an absolute quantity but appears to flow at a different rate depending on relative motion

Opened the road to quantum mechanics

Light “hits” like a particle

Light waves have “quantized” and “discrete” energies, depending on their wavelengths

Presented a revised theory of relativity

General relativity: space is curved

Foundation of modern cosmology

Einstein’s World

Reality of atoms and molecules in hot debate

Light poorly understood: “What was the medium light traveled in?”

Phenomena of radiation

Absorption lines in the Sun were observed, but could not be explained

Einstein helped clear these mysteries and began the era of modern physics.

Einstein’s Early Life and Career

Born in Ulm, German Empire in 1879, Albert Einstein excelled in physics and mathematics but failed in other subjects. Einstein dropped out of high school in 1895 and restarted school in Aarau, Switzerland, where he studied Maxwell’s works (~1870), which stated that electricity and magnetism obeyed the same set of physical laws — hence, electromagnetism. Einstein discovered that the velocity of light remained constant no matter the media. Although Einstein was brilliant, he irritated professors as he was too independent. In 1902, Einstein became a patent office clerk at the Swiss Patent Office in Bern. By 1905, Einstein had written six scientific papers, three of which explored the existence of molecules and the “kinetic theory.” For his other three papers, one published in March explained his light-quantum hypothesis (light hits like a particle), a fundamental step of quantum mechanics. For this, Einstein received a Nobel Prize in 1921. Another paper published in June was Einstein’s first paper on Special Relativity that explored light contraction and time dilation approaching the speed of light. In September of 1905, Einstein published his second paper on special relativity, in which he included the famous equation E = mc².

* General relativity includes gravity, while special relativity does not.

General Relativity and Special Relativity

Special Relativity

The laws of physics are the same in all uniformly moving reference frames, or in all directions

In any uniformly moving reference frame, the velocity of light (c) is the same whether emitted by a body at rest or a body in motion

Time Dilation and Length Contraction

Time Dilation: Time itself doesn’t tick at the same rate approaching the speed of light; instead, the time synchronization veers off; so approaching the speed of light, time appears to tick much slower.

Length Contraction: The lengths of moving objects are contracted when viewed by a stationary viewer

Mass and Energy

The mass of a moving body increases compared to its “rest mass” because it takes a bigger force to accelerate

Acceleration: speed gained in a given time

An object accelerating up is smaller because of time dilation; acceleration is harder the more massive the object is

At first, the scientific community met Einstein’s special relativity theory with silence, but Max Planck, who won the Nobel Prize for explaining black body radiation, realized the importance of Einstein’s work and publicized it; from 1906, scientists took notice and visited Einstein to talk about science

Einstein’s scientific circles grew stating 1908; became associate professor in 1911 and a professor of the Swiss Federal Institute of Technology in 1912

Einstein’s findings demanded a new way of thinking as Newton’s Law of Gravity was only valid from speeds much smaller than light

Einstein named the “birth of special relativity” “The Step”

1907: The Equivalence Principle – gravity corresponds to acceleration

1911: Bending of light in a gravitational field, a consequence of the Equivalence Principle, could be checked with astronomical observations

1912-1915: Extend relativity to objects moving in an arbitrary way with respect to one another

1915: General Relativity “Gravity curves space”: there’s no need for the “force” of gravity; all motion is along “straight lines” in curved space-time and matter tells space how to move

Evidence: starlight bends around the Sun; Mercury’s orbit will precede at a different rate than Newton predicted

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Astronomy: To Infinity and Beyond! Welcome to "The Cosmos." I will take you on a journey through our solar system, galaxy, and the Universe! You will be updated with current events in astronomy. Please click on the picture above to visit my blog on poetry, writings, and musings!

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References for photos used from websites can be found under the "References" page. Photo credit: news sites (reference included in post), NASA (most images used), and Google (for artists' view of objects unable to be photographed).